Bottle closure



W. LEARY BOTTLE CLOSURE June 1956 Filed June 9 4 INVENTOR ILLIAM W.LEARY TTORNE BOTTLE CLOSURE William W. Leary, East Lampeter Township,Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster,Pa., a corporation of Pennsylvania Application June 9, 1954, Serial No.435,496

2 Claims. (Cl. 215-40) This invention relates to a bottle closure and isconcerned more particularly with a molded type bottle closure having apolyethylene sealing liner disposed there- Molded bottle closures arecustomarily used on containers for preparations such as nail polish andother liquid and semiliquid preparations. Nail polish which includes asolvent which deleteriously affects most sealing liner compositions maybe satisfactorily sealed with a liner formed of a solid polymer ofethylene. Closures lined with polyethylene have been made heretofore andare disclosed in Dorough Patent 2,23 8,681.

One of the problems which has confronted the manufacturer producing thistype of closure is that of securing the solid polyethylene liner to themolded body of the closure to prevent separation of the two componentsduring shipment of the closures in bulk to the place of use, and alsoduring use when the sealing liner may adhere to the lip of the containerand be removed from the inside of the closure body when the closure isunscrewed from the bottle to which it is applied. As is well known,polyethylene liner materials cannot be secured readily to moldedclosures by the use of conventional adhesives, principally because ofthe inability of most adhesives to wet the waxy surface of thepolyethylene material.

While viscous adhesives have been developed for this purpose, they tendto string when the adhesive applicator head is withdrawn from inside theclosure, and this tends to contaminate the screw threads and sometimesthe lower edge and outer side wall of the closure. The problem ofstringing is particularly acute with applicator type closures whichinclude a well which projects from the center of the inner head surfaceof the closure and receives the stem of an applicator brush. An adhesiveapplicator head of annular configuration must be used to deposit theadhesive in the space between the well and the screw-threaded side wallof the closure, and it is diflicult with the viscous adhesives to avoidserious contamination of the wall of the well portion resulting fromstringing of the adhesive as the applicator head is withdrawn. The costof the adhesive and its application, as well as the higher cost ofinspection and the reworking of those closures which do not passinspection because of contamination of the closure body by adhesive,militate against the use of adhesive assembly where solid polyethyleneliners are used.

An object of the invention, therefore, is to provide a molded bottleclosure of the well type having a solid polyethylene sealing linerpositioned in the closure between the wall of the well and the side wallof the closure and held therein by interengagement between the sealingliner and a projection on the wall of the well, the liner thus beingsecured against dislodgment during transportation and normal use.

Molded plastic bottle closures for nail polishes and the like must bemass-produced at low cost in order to be competitive with other types ofclosures; and, accordingly, it is essential that the combination be soconstructed nitcd States Patent 2,748,969 Patented June 5, 1956 thatassembly of the sealing liner with the closure may be effected rapidlyso as not to be too costly.

It is an object of the present invention to provide a structureincluding a molded closure having a well and a solid polyethylenesealing liner, with the parts being so proportioned that the sealingliner may be rapidly assembled with the closure body on a massproduction basis with automatic assembly machines.

Other objects of the invention will be apparent from consideration ofthe following description of a preferred embodiment of the invention inconjunction with the attached drawing, in which:

7 Figure 1 is an enlarged cross-sectional view showing a well typemolded closure with a solid polyethylene liner received therein, and

Figure 2 is a detailed sectional view to a further enlarged scaleillustrating the relationship between the dimensions of parts of theclosure body and the liner.

Referring to Figure 1, there is shown a bottle closure which comprises amolded body having a head portion 2, a side wall portion 3 projectingfrom the periphery of the head portion, and a screw-threaded projection4 on the inner surface of the side wall portion. An applicator well 5projects from the center of the head portion 2 within the confines ofthe side wall portion 3 and has a tapered outer surface 6 which leadsfrom the upper edge 7 thereof to a generally annular liner-retainingprojection 8 directed from the well 5 toward the side wall portion 3 andspaced above the head portion 2. The well 5 is provided with a centralopening 9 which may receive the stem of a small brush or otherapplicator device.

A ring type sealing liner 10 of solid polyethylene material is receivedwithin the closure and is held in position against dislodgment by theline-retaining projection 8. It will be observed by reference to Figure1 that the outer diameter of the ring sealing line 10 is less than theminimum diameter of the side wall portion 3 at the screw threadprojections 4. The inner diameter of the ring sealing liner ispreferably somewhat less, generally in the order of .003" to .005" less,than the outer diameter 11 of the well 5 in the area between the headportion 2 and the liner-retaining projection 8. This insures that theliner will rest against the wall of the well behind the linerretainingprojection 8.

In order to facilitate rapid assembly of the sealing liner with theclosure and to permit the use of a solid polyethylene liner which in thethicknesses customarily used in lining closures is not susceptible tostretching to any substantial extent under the application of smallforces, preferred practice is to provide the tapered portion 6 on theWell and to so proportion the same that the diameter a as shown inFigure 2 will be less than the diameter 0 shown in that view, thedimension 0 indicating the diameter of the central opening in theannular sealing liner 10. This permits the sealing liner to be droppedinto the closure and over the top portion at least of the well 5, theliner being guided along the tapered surface 6. The diameter of theliner-retaining projection 8, which dimension has been indicated at b inFigure 2, is greater than the maximum inner diameter 0 of the sealingliner, so that when the liner has been forced over the projection itwill remain in its inserted position, being held against dislodgment bythe liner-retaining projection. Because of the nature of the solidpolyethylene material which is not as yieldable as gum rubber, forexample, it is necessary to so proportion the inner diameter of the ringsealing liner and the outer diameter of the liner-retaining projectionthat rapid assembly may be effected without the necessity of applyingforces of such magnitude as would possibly damage or break a relativelyfragile molded closure. For most practical purposes, the liner-retainingprojection 8 will be acceptable if it projects radially outwardly a dis-3 tance of .003" to .006" from the wall of the well. in other words, themaximum outer diameter of the linerretaining projection 8 will be from.006 to .012" greater than the diameter of the well in the areathereabove where the seated liner is positioned.

As shown in Figure 2, preferred practice is to provide theliner-retaining projection 8 in such position on the side wall of thewell that when the sealing liner is positioned thereover no substantialaxial movement of the liner with respect to the well will be permitted.A tolerance of .010 to .015 is generally provided, however, to insurethat in all instances the liner will be disposed fully above theliner-retaining projection. The liner-retaining projection is roundedthroughout to facilitate molding of the closure body and also to avoiddamage to the liner and to permit rapid assembly by forcing the linerover the linerretaining projection. While the liner-retaining projectionhas been indicated as competely annular, it may be segmented if desired,for it will perform the same function it so constructed. By use of theterm generally annular" in reference to the liner-retaining projection,it is intended to comprehend such modifications. As a typicalillustration of the dimensions of a satisfactory closure, reference ismade to a 33-millimeter bottle closure for application to a standardscrew-finished bottle neck. The diameter a cf the molded closure bodymay be .251", the diameter b .312", and the diameter of the wall of thewell above the liner-retaining projection may be .300". The sealingliner of solid polyethylene may be .040" to .050 thick, have an outerdiameter of 1.166 to 1.176", and an inner diameter of about .295" priorto assembly with the closure body or about .005 less than the .300"diameter of the well surface which it will engage when assembled, andabout .017 less than the diameter of the liner-retention projection overwhich it is forced during assembly.

I claim:

1. A bottle closure comprising: a molded body having a head portion, aside wall portion projecting from the periphery of the head portion, ascrew-thread projection on the inner surface of the side wall portion,an applicator well projecting from the center of the head portion withinthe confines of said side wall portion, a tapered outer sur face on saidwell leading from the outer edge thereof to a generally annularliner-retaining projection of generally semicylindrical shape projectingradially from said well toward said side wall portion and spaced abovesaid head portion and over which an annular sealing liner may be pressedaxially of said well, and a ring type sealing liner of solidpolyethylene snap-fitted within said closure over and held in positionagainst dislodgment by said linerretaining projection, the outerdiameter of said ring sealing liner being less than the minimum diameterof said side wall portion at said screw-threaded projection and theinner diameter of said ring sealing liner being less than the maximumouter diameter of said liner-retaining pro jcction and greater than theminimum outer diameter of said tapered outer surface of said wellportion.

2. A bottle closure in accordance with claim 1 in which theliner-retaining projection extends from the wall of the well about .003to .006".

References Cited in the file of this patent UNITED STATES PATENTS1,712,667 Hart May 12, 1929 2,039,757 Von Till May 5, 1936 2,046,804Youngblood July 7, 1936 2,160,517 Rabinowitz et al May 30, 19392,238,681 Dorough Apr. 15, 1941 2,263,653 Smith et a]. Nov. 25, 19412,348,515 Baumgartner May 9, 1944 2,431,303 Billmeyer Nov. 25, 19472,440,149 McGinnis Apr. 20, 1948

